The present invention relates to systems and methods for sanitizing pools and spas. In particular, the present invention relates to a single power source system for generating a sanitizer for a tandem swimming pool and spa.
Pools and spas have a circulation system that continually pumps water from the pool or spa through a filter, heater, and sanitizer feed system before returning the water back to the pool or spa. The circulation system is necessary to maintain the body of water at sanitary conditions. The water passes through the filter to reduce the accumulation of foreign material, such as hair, soil, or solids, in the pool or spa. Once the water has been filtered, the water passes through the heater, where the water is heated prior to returning to the pool or spa.
In addition to filtering, pool and spa water also requires regular sanitization in order to maintain hygienic conditions. Allowing sanitation levels to either fall below or rise above required specifications results in decreased efficiency of the system. Low levels of chemical sanitizer in the pool or spa can contribute to algae blooms, bacterial breakouts, cloudiness in the water, and chemical imbalances. A method for sanitizing pool or spa water is by adding sodium chloride (NaCl) to the pool or spa and passing the water containing sodium chloride through a chlorine generator where electrolysis converts the sodium chloride and water to sodium hypochlorite (NaOCl), by the following reaction:2NaCl(aq)+2H2O→Cl2(g)+H2(g)+2NaOH (aq)→NaOCl(aq)+H2O+NaCl(aq)+H2(g).
The chlorine generator is capable of being powered on and off depending on the concentration of chlorine in the water. When there is a sufficient level of chlorine in the pool or spa water, the chlorine generator is powered off and no reaction takes place. Thus, water circulating through the circulation system is filtered and heated, but the composition of the water is not altered. When the level of chlorine has fallen to a desired setpoint, the chlorine generator is powered on and the sodium chloride and water passing through the chlorine generator is converted to sodium hypochlorite. The chlorine generator remains powered on until the concentration of chlorine in the water has reached a desired steady state level.
Oftentimes, both a swimming pool and a spa are installed. Typically, the volume of the pool is on average ten to fifteen times larger than the volume of the spa. Despite this large difference in volumes, the cost of the equipment for treating the pool and spa is not significantly different. The need for two power sources, one supplying power to generate chlorine for the pool and the other supplying power to generate chlorine for the spa, can result in higher installation and maintenance costs for the tandem pool and spa.